1. Field of the Invention
This invention relates to an image processing apparatus having a printer function and a copying function, a reader controller mounted in such an apparatus, and a method for controlling the reader controller.
2. Description of the Related Art
In general, printing apparatuses include ink-jet printers, thermal transfer printers, electrophotographic printers and the like. The electrophotographic printers include, for example, laser-beam printers.
A description will now be provided of the configuration and the state of use of a laser-beam printer with reference to FIGS. 19 and 20. FIG. 19 is a schematic block diagram illustrating the configuration of a conventional laser-beam printer. FIG. 20 is a block diagram illustrating the state of use of the laser-beam printer shown in FIG. 19.
As shown in FIG. 19, the laser-beam printer includes an engine controller (hereinafter termed a "DC controller") 2002 for driving an image forming mechanism 2003 for executing a series of processing of conveying a sheet and forming an image represented by image data on the sheet, and a printer controller 2103 for data processing of generated image data by processing printing data transferred from a host computer 2104, setting an operation for the DC controller 2002, transmitting the image data at a predetermined timing corresponding to the DC controller 2002, and transmitting a command relating to the setting of the operation of the DC controller 2002. The image forming mechanism (engine) 2003, the DC controller 2002 and the printer controller 2103 are mounted in a main body 2001 of the printer together with an option controller 2006 (to be described later).
An optional sheet feeding cassette 2004 and a sorter 2005 are also mounted in the main body 2001 of the printer. Driving operations for the optional sheet feeding cassette 2004 and the sorter 2005 are controlled by the option controller 2006. The option controller 2006 controls driving operations for the optional sheet feeding cassette 2004 and the sorter 2005 based on commands from the printer controller 2103.
As shown in FIG. 20, the laser-beam printer can be used as a dedicated printer for the host computer 2104, or as a printer shared in a network. More specifically, when using the laser-beam printer as a dedicated printer for the host computer 2104, the printer controller 2103 is connected so as to be in communication with the host computer 2104, and performs processing, for example, analyzing printing data supplied from the host computer 2104, generating image data so as to be subjected to printing processing based on the analysis, and transmitting the generated data to a printer engine 2102, and outputs a control command relating to print output by the printer engine 2102. The image data and the control command are transmitted to the printer engine 2102 via a video I/F (interface) 2101. The printer engine 2102 is a unit which includes the image forming mechanism (engine) 2003, the DC controller 2002, the optional sheet feeding cassette 2004, the sorter 2005 and the optional controller 2006 shown in FIG. 19.
The printer engine 2102 prints the image data transmitted from the printer controller 2103 based on the control command from the printer controller 2103. Each processing to be executed during the printing operation, such as sheet feeding processing, printing processing, sheet discharging processing or the like, is controlled by the DC controller 2002 and the optional controller 2006.
Recently, multifunctional apparatuses have been developed. For example, by being combined with an image reading device and a host computer, the above-described laser-beam printer can realize a copying function. Alternatively, by incorporating an image reading device in the laser-beam printer, a composite apparatus having a printer function and a copying function is provided.
A description will now be provided of apparatuses having such functions with reference to FIGS. 21 and 22. FIG. 21 is a diagram illustrating a design of realizing a copying function by a laser-beam printer by being combined with an image reading device and a host computer. FIG. 22 is a diagram illustrating the configuration of a composite apparatus having a printer function and a copying function by incorporating an image reading device in a laser-beam printer.
In the design shown in FIG. 21, if the laser-beam printer is used as a dedicated printer for the host computer 2104 (as shown in FIG. 20), an image reading device 2501 is connected to the host computer 2104, and read data obtained from the image reading device 2501 is output to the printer controller 2103 via the host computer 2104, so that a copying function can be executed using the printer function of the laser-beam printer.
Alternatively, if the laser-beam printer is used as a printer shared in a network 2105 (as shown in FIG. 20), the image reading device 2501 is connected to the network 2105, and read data obtained from the image reading device 2501 is output to the printer controller 2103 via the network 2105, so that a copying function can be executed using the printer function of the laser-beam printer.
The composite apparatus shown in FIG. 22 includes a controller unit (printer controller) 2602 connected so as to be in communication with the host computer 2104, a reader unit (image reading device) 2502 for reading an image of an original, an I/F 2601 for connecting the controller unit 2602 to the reader unit 2502 so as to be in communication with each other, and a selector unit 2603 for selecting one of image data from the controller unit 2602 and image data from the reader unit 2502 and outputting the selected data to the printer engine 2102. In the composite apparatus having the above-described configuration, the selector unit 2603 selects one of image data from the controller unit 2602 and image data from the reader unit 2502 while confirming the operational states of the controller unit 2602 and the reader unit 2502 via the I/F 2601, and outputs the selected image data to the printer engine 2102, so that one of the printer function and the copying function can be executed.
However, in the configuration shown in FIG. 21, image data obtained from the image reading unit 2501 is output to the printer controller 2103 via the host computer 2104 or the network 2105 during the execution of a copying mode. Accordingly, a considerable time is required for transferring the image data output from the image reading device 2501 to the printer controller 2103, and therefore a copy output cannot be obtained in a real time.
In the composite apparatus shown in FIG. 22, since it is necessary to now provide the I/F 2601 for connecting the controller unit 2602 to the reader unit 2502, it is necessary to greatly change the hardware and software in order to provide a composite apparatus having a printer function and a copying function based on a conventional laser-beam printer, thereby providing a surplus time for the development of the apparatus, and a possibility of greatly increasing the production cost.